Canola yields rebound across Kansas in 2016

Canola yields at K-State Research and Extension trial sites and producer fields rebounded in 2016 after a couple of challenging years. The higher yields were primarily the result of a mild winter, adequate precipitation during the growing season, and optimum temperatures at grain filling.

The production year began with very favorable soil moisture conditions in most areas, except for north central Kansas. Establishment of the winter canola trial at the North Central Experiment Field near Belleville was erratic because of dry soils and thus the site was abandoned. All other trial sites entered the winter with ideal top growth and adequate soil moisture provided by late fall rains. Soils were saturated at some points in December and January across the state.

Producer canola yields in Kansas averaged around 45 to 50 bushels/acre, with a yield range from the mid-20s to upper 70s. Producers around Kiowa reported yields of 45 to 65 bushels/acre, and Harper County yields ranged from about 35 to 55 bushels/acre. Some producers in central Kansas reported somewhat lower yields, in the mid-20s to low-40s, mostly due to the effects of late spring freezes and insects. A producer near Concordia had yields that ranged from 42 to 67 bushels/acre. A producer in southwest Kansas reported a high yield of 59 bushels/acre under limited irrigation, but some of his yields were as low as 20 bushels/acre because of harvest losses caused by late-season heavy rainfall and wind events. With an average price of around $7.00/bushel at peak harvest, many producers were satisfied with the returns they received.

Yield trials that included commercial winter canola varieties were harvested at Conway Springs, Hutchinson, Kiowa, and Manhattan. The trial at Garden City was lost to rabbit feeding in fall 2015. A seven-year yield summary is provided in Table 1. Trial site yields reflected very closely the yields of producers in 2016. For a preliminary summary of 2016 yield results, please see the Kansas Crop Performance Testing website (http://www.agronomy.k-state.edu/services/crop-performance-tests/canola-and-cotton.html).

Yearly averages are very close to 40 bushels/acre, which is the yield potential we should expect from canola year-in and year-out. The 2015 losses were nearly 100% caused by the mid-November cold snap that occurred before the crop had been completely hardened off for the winter. More than likely the losses would have been much less had we experienced conditions favorable for developing winter hardiness prior to the cold snap. We also must remember that many producers still harvested canola in 2015, but the trial sites unfortunately did not fare so well.

Probably the biggest concern of the 2015/16 season was the leaf purpling that many producers observed as a result of anthocyanin build up in the leaves as temperatures turned colder. Anthocyanin production is a natural response to stress in winter canola. As a general rule, as the crop hardens off it will almost always have a purple tint to its leaves. There are a few reasons why the purpling was more evident this year. First, the saturated soils at that time of year caused some stress on the crop. Second, the purpling was more pronounced in fields that had lower N rates going into the winter. Deficiencies in available nutrients can cause stress on overwintering canola and result in anthocyanin production. Third, varieties differ in the amount of anthocyanin produced. As a general observation, hybrids tended to show less purpling than open-pollinated varieties. Part of the reason may be the increased fall vigor we see in hybrids as a result of rapid growth and a more extensive root system. Fourth, purpling seems to last longer in milder winters, primarily because the crop takes longer to go dormant.

Nonetheless, as temperatures warmed up in the spring and the canola began to break dormancy, the crop regained its green color and there was little evidence that the buildup of anthocyanin had any impact on final yields. It is presumed, however, that in some of the fields with lower rates of fall N, the anthocyanin and stunting resulted reduced yields. Other causes of yield loss in producer fields included late spring freezes at flowering; late-season insect infestations – primarily cabbage aphid, diamondback moth larvae, and lygus bugs; and shattering from severe thunderstorms.

Careful variety selection is very important for producing winter canola. Watch future Agronomy eUpdates for a review of winter canola varieties and suggestions to help with variety selection. Despite any of canola’s recent struggles, many producers are encouraged by canola’s resiliency and the benefits it provides to their cropping systems.